Bi-directional scalable intra-panel interface

Abstract

A touch panel display subsystem for bi-directional intra-panel communication includes a forward link and a backward link between a timing controller and one or more source drivers. The forward link includes a timing controller transmitter in the timing controller to receive video signal, video control signal and touch control signal, and to transmit over the forward link in the format of frame based packet, and a source driver receiver in the source driver to receive video signal, video control signal and touch control signal over the forward link. The backward link includes a source driver transmitter in the source driver to receive the touch sensor data and transmit the touch sensor data over the backward link when the backward link is enabled, and a timing controller receiver in the timing controller to receive the touch sensor data over the backward link when the backward link is enabled.

What is claimed is: 
     
       1. A method for intra-panel communication, the method comprising:
 establishing a forward link between a timing controller and one or more source drivers in a group of source drivers; 
 transmitting, from the timing controller to the one or more source drivers over the forward link, a composite video signal, the composite video signal comprising video data, a video control signal, and a touch control signal specifying an operation mode of a backward link between the timing controller and the one or more source drivers; 
 establishing the backward link when the operation mode specified by the touch control signal has a first operation mode; 
 receiving touch sensor data from a touch sensor, the touch sensor coupled to each source driver included in the group of source drivers; 
 transmitting, over the backward link, the received touch sensor data from the one or more source drivers in the group of source drivers to the timing controller; and 
 disabling the backward link in response to a determination that the transmitting of the received touch sensor data is complete. 
 
     
     
       2. The method of  claim 1 , further comprising transmitting the touch control signal over the forward link to the one or more source drivers during a vertical blanking period. 
     
     
       3. The method of  claim 1 , further comprising transmitting the touch control signal over the forward link to the one or more source drivers during an intra-frame pause. 
     
     
       4. The method of  claim 1 , wherein the first operation mode is an active operation mode. 
     
     
       5. The method of  claim 1 , further comprising maintaining the backward link in a disconnected state when the touch control signal has a second operation mode representing an idle operation mode. 
     
     
       6. The method of  claim 1 , wherein transmitting, over the backward link, the received touch sensor data from the one or more source drivers in the group of source drivers to the timing controller further comprises:
 extracting a clock signal from the composite video signal; and 
 transmitting the received touch sensor data to the timing controller over the backward link at a clock rate derived from the clock extracted from the composite video signal. 
 
     
     
       7. The method of  claim 6 , wherein the clock rate is the same rate or sub-rate of the clock signal extracted from the composite video signal. 
     
     
       8. The method of  claim 6 , further comprising scrambling the touch sensor data using a scrambler included in a backward link signal path of the one or more source drivers. 
     
     
       9. The method of  claim 1 , wherein disabling the backward link further comprises:
 generating a descrambled composite video signal by a de-scrambler circuit included in forward link signal path of the one or more source drivers, the descrambled composite video signal comprising the touch control signal; 
 receiving, by a touch receiver included in a backward link signal path of the one or more source drivers, the touch control signal; and 
 disabling the touch receiver when the touch control signal specifies a second operation mode representing an idle operation mode. 
 
     
     
       10. The method of  claim 9 , further comprising disabling a transmitter included in the backward link path of the one or more source drivers when the touch control signal specifies the second operation mode. 
     
     
       11. The method of  claim 9 , further comprising:
 receiving, by a receiver included in a backward link path of the timing controller, the touch control signal; and 
 disabling the receiver included in the backward link path of the timing controller when the touch control signal specifies the second operation mode. 
 
     
     
       12. The method of  claim 1 , wherein disabling the backward link responsive to a determination that the transmitting of the received touch sensor data is complete comprises:
 receiving a touch controller command indicating an expected amount of touch sensor data to be transmitted by the touch sensor; 
 retrieving, by a touch receiver, the touch sensor data; 
 comparing an amount of retrieved touch sensor data to the expected amount of touch sensor data; and 
 disabling the backward link when the amount of retrieved touch sensor data equals the expected amount of touch sensor data. 
 
     
     
       13. A system for intra-panel communication, the system comprising:
 a forward link comprising:
 a timing controller transmitter included in a timing controller, the timing controller transmitter configured to:
 receive a composite video signal, the composite video signal comprising video data, a video control signal, and a touch control signal, and 
 transmit the touch control signal over the forward link, and 
 
 
 a source driver receiver included in a source driver coupled to receive the composite video signal from the timing controller transmitter over the forward link; and 
 a backward link comprising:
 a touch receiver included in the source driver, the touch receiver coupled to receive touch sensor data from a touch sensor, and configured to enable the backward link in accordance with an operation mode specified by the touch control signal; 
 a source driver transmitter included in the source driver, the source driver transmitter configured to receive touch sensor data from the touch receiver, and transmit the touch sensor data over the backward link when the backward link is enabled, and 
 a timing controller receiver included in the timing controller coupled to receive the touch sensor data from the source driver transmitter over the backward link when the backward link is enabled. 
 
 
     
     
       14. The system of  claim 13 , wherein the forward link operates in accordance with a scalable intra-panel interface format. 
     
     
       15. The system of  claim 13 , wherein the forward link further comprises:
 a touch controller configured to:
 receive one or more touch controller commands from an external processor and generate the touch control signal; and 
 generate a receiver control signal based on the one or more touch controller commands. 
 
 
     
     
       16. The system of  claim 15 , wherein the touch controller is further configured to enable the timing controller receiver when the one or more touch controller commands indicates the operation mode specified by the touch control signal has a first operation mode. 
     
     
       17. The system of  claim 15 , wherein the touch controller is further configured to disable the timing controller receiver when the one or more touch controller commands indicates the operation mode specified by the touch control signal has a second operation mode. 
     
     
       18. The system of  claim 13 , wherein the source driver comprises:
 a clock data recovery circuit coupled to receive an output of the source driver receiver and configured to generate a recovered clock, the source driver transmitter transmitting the touch sensor data at a clock rate based on the recovered clock. 
 
     
     
       19. The system of  claim 13 , wherein the touch receiver is configured to enable the source driver transmitter when the operation mode specified by the touch control signal has a first operation mode. 
     
     
       20. The system of  claim 13 , wherein the touch receiver is configured to disable the source driver transmitter when the operation mode specified by the touch control signal has a second operation mode. 
     
     
       21. The system of  claim 13 , wherein the timing controller further comprises a touch signal processor coupled to receive the touch sensor data from the touch receiver when the touch receiver is enabled.